Debian Stretch upgrade and ISPC 3.1.6

Hi. Does anyone meet that problem after upgrade to Debian Stretch?
1 . After installation of a new remote server (slave) and conection to Main Server new MYSQL user on Main Server cannot be addeded
2. After adding by hand scripts dont start
3. When trying to uninstall ISP on remote server (slave) I have this monit:
PHP Warning: mysqli_connect(): (HY000/1045): Access denied for user 'ispcsrv20’@‚xx.xx.xx.xx' (using password: YES) in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 85